Shower pump switch

[Sea Dog]

29 minutes ago, Ssscrudddy said:

I'm confused now, some are saying don't use a 240V switch while another says it's ok.
I too have a whale gulper for my shower waste pump. I wired it up with a bog standard light switch from Screwfix. So is this ok or not?

Yes, it's OK... until its not, because the contacts have burned out through arcing they were not designed to handle. The period is indeterminate, but will be longer with a correctly rated 12V DC switch. My money would go on buying the right switch for the job in the first place. Others will, and are welcome to, see things differently... with varying results. 

[Tony Brooks]

1 hour ago, Ssscrudddy said:

I'm confused now, some are saying don't use a 240V switch while another says it's ok.
I too have a whale gulper for my shower waste pump. I wired it up with a bog standard light switch from Screwfix. So is this ok or not?

Its not best practice and if a professional did it I expect you would have a good case against them but we all know using AC switches for DC is very common, especially on inland boats. Whilst I would never feel happy advising someone that it is OK pragmatically if it ain't broke don't fix it. The time to change is when it is broke.

[GUMPY]

1 hour ago, Ssscrudddy said:

I'm confused now, some are saying don't use a 240V switch while another says it's ok.
I too have a whale gulper for my shower waste pump. I wired it up with a bog standard light switch from Screwfix. So is this ok or not?

Its fine until it fails which probably wont be in your lifetime. 

All my switches, lights and pumps are 230v domestic type switching 12vnd I've yet to have a failure. I have lost count of the number of toggle switches that have failed which is why I have been using domestic ones for the past 25 years

Edited May 11, 2017 by Loddon

[bizzard]

You can often pick up old domestic DC light switches at car boots ect. The nicest have a ceramic base with brass or chrome plated caps. DC should be written on the bottom, if in doubt unscrew the top cap to check the beautiful knife action.

[Alan de Enfield]

2 hours ago, Ssscrudddy said:

I'm confused now, some are saying don't use a 240V switch while another says it's ok.
I too have a whale gulper for my shower waste pump. I wired it up with a bog standard light switch from Screwfix. So is this ok or not?

You won't die, or the boat sink because you have used it, but you may find one-day that the contacts in the switch have welded themselves together and the pump runs continuously.

[rusty69]

I have had the same whale gulper on a 240v switch for last 17 years. Switch has been replaced once in that time due to failure. Not sure why it failed. 

[jddevel]

On ‎10‎/‎05‎/‎2017 at 11:44, Tony Brooks said:

Get a pattress blanking plate (like a switch but with no gubbins mounted on it) and drill it to accept whatever 12V switch you choose

Good bit of lateral thinking. Was looking for an easy solution soon as I read it I thought of course. However may make up a nice oak pattress

[Neil2]

2 hours ago, Loddon said:

Its fine until it fails which probably wont be in your lifetime. 

All my switches, lights and pumps are 230v domestic type switching 12vnd I've yet to have a failure. I have lost count of the number of toggle switches that have failed which is why I have been using domestic ones for the past 25 years

Well I for one am totally confused by this thread.  My 30 year old boat also has 240v domestic switching and it's all original.  I fitted an 12v switch to the water pump in a more convenient location and it failed within a year (I replaced it with a 240v switch).   I understand the theory, but if your experience tells you otherwise..?    

[rusty69]

7 minutes ago, Neil2 said:

Well I for one am totally confused by this thread.  My 30 year old boat also has 240v domestic switching and it's all original.  I fitted an 12v switch to the water pump in a more convenient location and it failed within a year (I replaced it with a 240v switch).   I understand the theory, but if your experience tells you otherwise..?    

Whats confusing. Its not best practice, but will probably work. So best to advise best practice i. e fit a suitably rated 12v dc switch. 

[Robbo]

On 10/05/2017 at 11:44, Tony Brooks said:

Get a pattress blanking plate (like a switch but with no gubbins mounted on it) and drill it to accept whatever 12V switch you choose.

Also look at CBE switches, the are aimed at the caravan market and do 12 and 240v thingys.

[Tony Brooks]

26 minutes ago, Neil2 said:

Well I for one am totally confused by this thread.  My 30 year old boat also has 240v domestic switching and it's all original.  I fitted an 12v switch to the water pump in a more convenient location and it failed within a year (I replaced it with a 240v switch).   I understand the theory, but if your experience tells you otherwise..?    

If you could be construed as passing yourself off as an expert (legal terms) and you advised it was OK to use AC switches on DC when it clearly is not then if there is a mishap or failure you would face more music than someone who has never claimed to be an expert or who has given reasonable grounds for others to assume they are an expert.

All those with knowledge have said is that it is bad practice to use AC switches for DC. That is all. The reasons have been explained. It has even been pointed out that the use of such switches seem to work with adequate life.

The fact that some with nothing to lose have chosen to question the best practice advice is what has caused any confusion. I very much doubt that AC switches used for DC operations is permitted under the RCD.

[Neil2]

4 hours ago, Tony Brooks said:

If you could be construed as passing yourself off as an expert (legal terms) and you advised it was OK to use AC switches on DC when it clearly is not then if there is a mishap or failure you would face more music than someone who has never claimed to be an expert or who has given reasonable grounds for others to assume they are an expert.

All those with knowledge have said is that it is bad practice to use AC switches for DC. That is all. The reasons have been explained. It has even been pointed out that the use of such switches seem to work with adequate life.

The fact that some with nothing to lose have chosen to question the best practice advice is what has caused any confusion. I very much doubt that AC switches used for DC operations is permitted under the RCD.

Does anyone have access to whatever the current ISO standard is? 

[Sea Dog]

Changed my mind: probably better as a new thread. 

Edited May 11, 2017 by Sea Dog
See above!

[Chewbacka]

15 hours ago, Neil2 said:

Does anyone have access to whatever the current ISO standard is? 

Available on the Manchester library web site.  -  

BS EN ISO 10133:2012
Small craft. Electrical systems. Extra-low-voltage d.c. installations.
Status: Current  |  Published 31/01/2013

BS EN ISO 13297:2014
Small craft. Electrical systems. Alternating current installations.
Status: Current  |  Published 31/12/2014

[mross]

I believe you need to be a member to access online but most public libraries will give you this access when you become a member.  Membership is free.

Edited May 12, 2017 by mross

[rjasmith]

20 minutes ago, mross said:

I believe you need to be a member to access online but most public libraries will give you this access when you become a member.  Membership is free.

Just a small correction to this from my experience of using library membership to access the BSOL website to read BS or ISO standards. As you say this facility used to be available quite widely via County Libraries. Anyone can join the County Library for free provided they are resident in that county or in an adjacent county or have an accommodation address there.

Once a member, you could either access BSOL online from anywhere by logging on with your library membership id or physically visit a local library and log on using one of their in house pcs. 

Unfortunately many if not most County Libraries have now dropped this service following price hikes by BSOL for the access licence combined with County Councils having to cut costs in the library service. Over the years I lost access from Surrey, then West Sussex, then Hampshire and finally Cambridgeshire. These four counties have even removed access via their in house pcs.

Manchester City Library however stands out as a splendid exception! First of all, they allow ANY UK resident to be a member of MCL and you can join online. Secondly, to use BSOL via their website doesn't seem to require you to log on so I suppose it isn't really necessary to join. I just thought I should join in case the number of members might be linked to securing library service funds or something.   

Richard

   

[Bewildered]

22 hours ago, jddevel said:

Good bit of lateral thinking. Was looking for an easy solution soon as I read it I thought of course. However may make up a nice oak pattress

You are far better off making up a nice oak pattress plate, the plastic ones are brittle, a bugger to drill and likely to snap; the metal ones are so hard they will burn out your drill bit.

As an installations engineer I have drilled pattress plates out many times to mount various bits of kit, I would suggest, if using plastic, buying several spares for when they break. Also screw the pattress down to a scrap piece of wood and drill very slowly, even then it only takes the drill bit to catch on one of the ribs to make it snap. You could use either a hole saw of the correct size or a cone cutter. If using a metal pattress use plenty of oil to cool the bit or you will scorch it.

[jddevel]

Thanks Bewildered. Oak pattress made using an off cut from one of the pothole frames I`ve made. Would have used mortice machine if I was going the plastic way- your right difficult to cut/drill however I would also have considered if not in the workshop using a tile diamond hole drill bit with a bit of insulating tape if necessary to get it started although if used on a tilted edge normally starts OK. Thanks again though.

[blackrose]

This all seems far too complex. For my whale gulper I just used a big white round 12v switch from the chandlers for about a fiver. It's been working fine for about 12 years.

[jddevel]

Point was Blackrose that as stated earlier the hole in the panelling was already cut to accept a domestic studwall type pattress  since sorted.